import threading

loop = 100000
number = 0

def _add(count):
    global number
    for _ in range(count):
        number += 1

def _sub(count):
    global number
    for _ in range(count):
        number -= 1

t1 = threading.Thread(target = _add,args=(loop,))
t2 = threading.Thread(target = _sub,args=(loop,))

t1.start()
t2.start()

t1.join()
t2.join()

print(number)